Optoelectronic oscillator

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A photonic BPSK modulation with 2.5 GHz RF signal from a microwave optoelectronic oscillator

A photonic BPSK modulation with 2.5 GHz RF signal from a microwave optoelectronic oscillator

The optical signal of MZIM after being detected by a photodetector, results in a BPSK modulated microwave carrier. III. OPTOELECTRONIC OSCILLATOR - OEO The figure 2 shows the block diagram of OEO as originally proposed [11]. The OEO is a ring structure with an MZIM followed by a feedback loop. The length of the optical fiber provides the time delay, τ , of the feedback loop, which de- termines the spacing between resonant frequency components. This time delay determines also the Q factor and OEO phase noise signal output.

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A photonic QPSK modulation in 2 GHz with an RF signal from a microwave optoelectronic oscillator

A photonic QPSK modulation in 2 GHz with an RF signal from a microwave optoelectronic oscillator

Due to the progressive evolution of Microwave Photonics (MWP) and constant evolution of the optoelectronic compo- nents [3], [4], [5], the European Space Agency (ESA) has been conducting a program of Research and Development to study the application of photonics in satellites since 2002 [6]. Taking advantage of the characteristics of photonic technology and its use in space environment, a circuit that achieves QPSK modulation directly at the carrier microwave frequency was as- sembled and characterized. To achieve the desired microwave carrier an optoelectronic oscillator (OEO) was used, resulting in a photonic system with reduced mass and volume.
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VCSEL Based Optoelectronic Oscillator (VBO) for 1.25 Gbit/s RZ Pulse Optical Data Generation

VCSEL Based Optoelectronic Oscillator (VBO) for 1.25 Gbit/s RZ Pulse Optical Data Generation

Abstract— We present the implementation results of a VCSEL based optoelectronic oscillator (VBO) in terms of phase noise and time jitter in the electrical and optical domain. The electrical signal at 1.25 GHz is used as a clock for Non- Return-to-Zero (NRZ) data generation. A system for optical pulse data generation to obtain duty cycles (DC) lower than 30% is proposed and simulated.

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Low Phase Noise Digital Division by 2 and by 3 of a 30 GHz Coupled Optoelectronic Oscillator

Low Phase Noise Digital Division by 2 and by 3 of a 30 GHz Coupled Optoelectronic Oscillator

* CNES, 18 Avenue Edouard Belin, Toulouse, France { 1 arnaud.collet, 2 olivier.llopis, 4 eric.tournier}@laas.fr, 3 Gilles.Cibiel@cnes.fr Abstract — A frequency synthesis technique based on the division of a coupled optoelectronic oscillator (COEO) reference is presented. This technique overcomes one of the main issues of the most common frequency synthesis technique, namely the phase locked loop (PLL) : the inherent phase noise degradation of frequency multiplication. In order to keep the benefits of the frequency division technique, residual phase noise of the dividers has to be reduced as much as possible. This article discusses the results of two digital dividers, a divider by 2 and a divider by 3, both with a 30 GHz COEO reference.
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O-band and C-band VCSEL based optoelectronic oscillator (VBO) for 1.25 Gbit/s pulsed RZ-OOK and RZ-DPSK free space optical transmissions

O-band and C-band VCSEL based optoelectronic oscillator (VBO) for 1.25 Gbit/s pulsed RZ-OOK and RZ-DPSK free space optical transmissions

Many telecommunication systems require high-frequency signals that can be used as carrier signals, synchronization patterns or in data generation. An alternative to microwave signal generation systems are optoelectronic systems. These systems improve the performance of the transmission systems due to the high spectral purity and reduced phase noise of the generated signal. One important architecture is the optoelectronic oscillator (OEO) proposed by S. Yao and L. Maleki [2]. Its structure uses electronic and optical components that can be modified to obtain signals with different characteristics regarding their quality, resonance frequency and applicability. An OEO modification was introduced in 2007 [3]. In this case, the optical modulator is removed and a
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Optoelectronic oscillator with delay elements in optical and RF domain

Optoelectronic oscillator with delay elements in optical and RF domain

1. INTRODUCTION The generation of radio frequency signals in the GHz range by optical devices have a natural compatibility with optical distribution networks and the transmission of microwave signals through optical fibers [1]. Early authors proposed a photonic system for microwave generation with low phase noise [2–4]. The proposed system is known as optoelectronic oscillator, OEO. It converts the energy of continuous laser light into spectrally pure microwave signals [2, 5].

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2.49 GHz low phase-noise optoelectronic oscillator using 1.55μm VCSEL for avionics and aerospace applications

2.49 GHz low phase-noise optoelectronic oscillator using 1.55μm VCSEL for avionics and aerospace applications

The VCSEL has threshold and rated currents of 1.58 mA and 12 mA respectively. The bias point was chosen to be at 6 mA so as to utilize the linearity of the device. The output optical power at 6 mA is 0.85 mW. The conversion efficiency of the VCSEL is 0.125 mW/mA. The RF amplifier connected to the RF filter has a gain of 35 dB. During the course of this experiment fiber-rolls of 100, 200, 300, 700 and 1000m lengths were used. All the fiber-rolls used were of Corning SMF-28 type. The output power of the oscillator signal varied from approximately 16 dBm to 20 dBm, depending on the length of the fiber-loop used to generate the signal. The output power, naturally, varies in inverse proportionality to the length of the fiber. The choice of fiber length was limited by VCSEL output optical power. For an optical fiber longer than 1000m , the attenuation of the optical signal becomes non-negligible and the oscillation conditions are not satisfied. Phase-noise curves at an offset of 1 kHz from the carrier to an offset of 100 kHz from the carrier have been plotted using the ESA. The 3-dB linewidth of the signal has also been measured using the ESA.
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Optical disk resonator with microwave free spectral range for optoelectronic oscillator

Optical disk resonator with microwave free spectral range for optoelectronic oscillator

II. INTRODUCTION The generation of microwaves from optics is an emerging field, which find potential applications in ra- dar, space, high speed telecommunications, and other domains of technology. A well known solution in op- toelectronic consists in implementing in the oscillator loop a long fiber optics delay line (a few km) between two optical–to–electrical convertors, i.e. a light mo- dulator, and a photodiode [1]. The long delay τ of a few 10s of µs is allowed due to the very low absorp- tion of modern telecoms grade fiber ; the delay plays the role of the storing energy element in the oscil- lator, which is usually performed by a resonator in classical electronic oscillators. The delay τ has a com- parable role with respect to the resonator relaxation time τ = Q/πν [2]. The optoelectronic delayed feed- back loop can thus oscillate at all frequencies multiple
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Phase Noise Study Based on Transfer function in Coupled Optoelectronic Oscillators

Phase Noise Study Based on Transfer function in Coupled Optoelectronic Oscillators

Keywords—Phase noise, optoelectronic oscillators, quality factor, power spectral density (PSD). I. INTRODUCTION The important rise of advanced telecommunication and signal processing systems in the past decades has increased the necessity for high spectral purity microwave and millimeter wave oscillators. Frequency multiplication from highly stable sources, such as quartz sources, is limited by the increase of the noise floor, which is often prohibitive at millimeter wave frequencies. On the contrary, microwave-photonics techniques become very efficient to generate highly stable signals in this frequency range [1] [2] [3]. One of the most popular microwave photonics techniques is the optoelectronic oscillator (OEO) which uses optical storage energy elements to achieve high spectral purity [1] [3] [4] [5]. The best phase noise performance at 10 GHz has been achieved using a 16 km delay line [6]. However, an efficient spurious mode suppression technique has to be implemented in this type of OEOs, since the bandwidth of an RF filter is not narrow enough to suppress the unwanted modes. A solution to get high equivalent Q factor, compact size and low spurious modes is to replace the optical delay line by an optical resonator [3,4]. However, this approach requires to set up an optical locking approach between the laser and the resonator. If a positive gain element is included in the resonator, an optical oscillator can be realized and the laser source and the resonator become the same device. The first architecture of this type has been proposed at the end of the 1990’s [5]. In such a system, a mode-locked laser is coupled to a microwave oscillator (COEO) [7, 8, 9, 10]. The COEO behaves like a resonator based OEO, because the optical signal is going through an optical loop (which increases the effective Q factor) but with an optical source which is part of the system and which intimately depends on the RF signal it generates.
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Merging of optoelectronic techniques for microwave signal generation

Merging of optoelectronic techniques for microwave signal generation

Several architectures have been proposed to optically generate microwave signals. The first one is the optical hererodyning using two frequency-offset lasers [1]-[2]. This is one of the most interesting techniques because of the high achievable frequencies and the wide tunability. Nevertheless, even if spectral purity and phase noise can be improved by using an optical phase-locked loop or an optical injection locking, the use of two lasers and the complexity of the feedback loop make this system power consuming and noisy. In the same way, a second technique is based on the beat- signal obtained from a bimode laser [3], whose interest is to correlate the frequency drifts of the two laser modes, but whose drawback is a weak accordability. The well-known optoelectronic oscillator using a long, fibered feedback loop provides a microwave signal presenting a very high spectral purity [4]. New configurations have appeared to rise in frequency. We review in this paper the dual-loop optoelectronic microwave oscillator and present a new technique of harmonic generation taking advantage of the good features of the ring oscillator. We present also two ways leading to a low-cost high integration of such systems,
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Quartz Crystal Oscillator Classification by Dipolar Analysis

Quartz Crystal Oscillator Classification by Dipolar Analysis

III. O SCILLATOR A MPLIFIER C LASSIFICATIONS A large number of amplifier circuits can be used to build an oscillator each having its own advantages and drawbacks. The choice among the different circuits is of course dictated by the application the oscillator will be used in, and also by technical considerations such as: frequency range, output power range, frequency stability, output wave- form, phase noise, etc. [9]. Even for a given set of specifica- tions there are many different circuits able to meet them and a particular choice is often a matter of personal or collective experience or skill rather than the conclusion of a methodi- cal analysis. It is not our claim to give a methodical reason- ing leading to an optimal circuit, but more modestly, to give the designer an efficient tool to help him to make a good choice.
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Towards an electrically-injected optical parametric oscillator

Towards an electrically-injected optical parametric oscillator

When a nonlinear medium is placed inside a cavity, a threshold may occur when its parametric gain exceeds losses, similarly to a laser threshold. This system is called an optical parametric oscillator (OPO). Like lasers, OPOs offer a coherent and monochromatic output, and moreover they are continuously tunable over hundreds of nanometers. Many macroscopic OPOs have been developed specifically for spectroscopic sensing in the NIR or MIR [36,37] , and some companies offer in situ diagnostics based on these tools (e.g. Blue Industry and Science, Quantel Lasers). However, they are more delicate to control than lasers. This is mostly due to the phase-matching condition: waves at different frequencies must stay in phase, which sets a constraint on their refractive indices. For example, in the case of SHG, indices of fundamental and harmonic must be equal. This being generally impossible because of chromatic dispersion, birefringence is often used for frequency conversion. The phase-matching condition limits the types of suitable materials and makes OPOs very sensitive to environmental variations. To date, OPOs mostly remain bulky lab-based systems, operated by specialists of nonlinear optics.
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Controlling nanomaterial self-assembly for next generation optoelectronic applications

Controlling nanomaterial self-assembly for next generation optoelectronic applications

We note that the peak absorption of these nanocrystals did not change during this time (Figure 2.11c), meaning any changes in the superlattice are likely due to ligand changes and not [r]

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Study of the optoelectronic properties of atomically thin WSe2

Study of the optoelectronic properties of atomically thin WSe2

Dans les tungsténides tels WS2 et WSe2 au contraire, les excitons les plus bas en énergie sont construits à partir de bandes entre lesquelles les transitions optiques sont interdites car[r]

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Random oscillator with general Gaussian noise

Random oscillator with general Gaussian noise

(Dated: November 21, 2018) We study the long time behaviour of a nonlinear oscillator subject to a random multiplicative noise with a spectral density (or power-spectrum) that decays as a power law at high frequencies. When the dissipation is negligible, physical observables, such as the amplitude, the velocity and the energy of the oscillator grow as power-laws with time. We calculate the associated scaling exponents and we show that their values depend on the asymptotic behaviour of the external potential and on the high frequencies of the noise. Our results are generalized to include dissipative effects and additive noise.
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Development of novel organic optoelectronic technologies for biomedical applications

Development of novel organic optoelectronic technologies for biomedical applications

between different wavelengths, since their optical absorption band is wide and difficult to manipulate. Organic active materials and devices have shown great potential in the tunability [r]

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Semiconducting Materials Based on Donor/Acceptor Units for Optoelectronic Applications

Semiconducting Materials Based on Donor/Acceptor Units for Optoelectronic Applications

In this work, we designed, synthesized, and characterized new self-organized semiconducting materials based on donor/acceptor architectures presenting high luminescence[r]

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A pulsed crystal oscillator range calibrator

A pulsed crystal oscillator range calibrator

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB. NRC Publicat[r]

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Force Sensing with an Optomechanical Self-Oscillator

Force Sensing with an Optomechanical Self-Oscillator

a thickness of 200 nm. Let us first examine the condi- tions to transform such a resonator into an optomechanical self-oscillator. Figure 2(b) shows a series of rf spectra of the output light of the optomechanical system, around the frequency of the first-order RBM. The spectra are acquired in ambient conditions, as the pump laser is blue detuned on the flank of an optical WGM resonance and its wavelength progres- sively increased to reduce the detuning. As the detuning is decreased, the number of photons injected into the res- onator increases, which intensifies optomechanical effects. Under these conditions, the mechanical RBM motion is progressively amplified along the series of curves, up to the point where the amplification overcomes mechanical losses and the spectral resonance abruptly narrows. At this point, the motion is self-sustained into an harmonic trajec- tory (see phase-space representations in Appendix A ).
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Jamming applications of a periodically quenched oscillator

Jamming applications of a periodically quenched oscillator

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB. NRC Publicat[r]

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